Weatherproof and decay-proof material



Patented Apr. 24, 1928.

UNITED STATES PATENT OFFICE.

IDOZIER FINLEY, OI. CALIFORNIA, ASSIGNOB TO THE PARAIIINE OOH-- PANIES,INC 01 SAN FRANCISCO, CALIFORNIA, A CORPORATION OF'DELAWARE.

wnarnaaraaor AND DECAY-PROOF MATERIAL,

No Drawing.

I a sheathing of material on a felt or woven fabric base which issaturated with a bitu-' minous composition and on which is a sur- 5 facecoating of a bituminous composition of relatively harder nature.

One of the objects of the invention is theproduction of a material whichis waterproof and weather-proof in high degree when subjected toexposure as on a roof,

and whichatthe same time is both waterproof and decay-proof when buriedin the ground, or used as a protective covering on subsurfacestructures, such as on the exterior face of basement walls, or as acovering for steel pipes such as those used in oil pipe lines.particular object of the in-.

vention is the roduct-ion of a material for covering the pipes ofoilpipe lines to .revent deterioration of the steel pipe by a kaline'orother corrosive elements in the soil.- This involves the use of amaterial which is in itself highly resistant to deterioration resultingfrom the presence of molds, bacteria and enzymes, and a material capableof a relatively permanent retention of its pliability. I

My invention includes other objects and features or advantages some ofwhich with the foregoing will be set forth in the following descriptionof my invention. It is to be understood that I do not limit myself tothe showing made by said description, as I may adopt variations of thepreferred embodiment of my invention within the scope of the appendedclaims.

For many years it has-been the practice to use fabrics or sheets ofmaterials saturated with compounds of bituminous character for variousprotective purposes including use on steel pipes which were to be buriedin the ground. and to which the material was ap plied by wrapping, thewrapped sheets being bound in place with wire. Such material has alsobeen used extensively in building, as a roofing material and alsoagainst the outer walls of the substructure of the building to preventthe ingress of ground water. It has also been used as a flume lining inirrigation work.

Material of this character, as applied to the uses mentioned, has notbeen sucessful except in the field of roofing where it has attained awidev usefulness. It should be Application filed August 6, 1923. SerialNo. 656,125.

noted however that in the field of roofing materials, such fabrics havebeen subjected to a wetting only at intervals and usually there is notime duringany one periodwhere the material is continuously moist longenough for decay to set in and progress to any great extent. The generalsuccess of such material when used for roof'coverings is overshadowed bythe rather unsuccessful use when applied underground, and this has givenrise to the widespread beliefthat the use of such sheets for roofcoverings is a wholly independent problem unrelated to their useunderground. In considering the application of such material tounderground or subaqueous work, the proper viewpoint is to" consider itas a heretofore unsuccessful phase of one general problem.

The important purpose of my invention therefore is the production at areasonable cost of a fabric or material of the nature above described,which is a distinct improvement over existing materials, and one capableof universal application. In this respect it differs essentially fromall other fabrics of the same broad class, in so far as their best andlongest service is confined to a relatively narrow field of usefulness.My invention produces by a single formula or group of formula usedtogether, a single material the equivalent of which has heretofore beenonly produced by several formulae productive of two or more distinctmaterials. This results in a simpler manufacturing problem, in reductionof the number of commodities to be handled by the salesman, and in fewerarticles to be stocked by the dealer.

My composition herein described does not appear to have been used by anyof the various experimenters who have worked in this field. It isprobable that admixtures of saponifiable ingredients. have been used,

rather than those herein described for the direction from the admixtureof parafiine wax and petroleum greases herein described because theasphalts which are produced in the eastern portions of the United Statesare already overly rich in grease and wax like constitutents.

In general it may be said that the prior art.

although disclosing some if not all of the constituents hereindescribed, has not been productive of a material having thepossibilities of universal application exhlbited by the fabric or sheetmaterial of this invention. Earlier materials fall short of theuniversality of my material, because where the saturant and the coating,if coating was, employed, were exclusivel of coal-tar pitch, coal tar oradmixtures oft less with other corresponding or related tar products,the general result has been that the fabric dries out rapidly whenexposed to the weather, becomes brittle and lifeless and rapidilydisintegrates.

. Where the saturant was wholly asphaltic in nature or comprisedasphaltum blended with rosin or wax taillngs or other petroleumproducts, and where a coating of like but harder composition wasemployed, the fabric usually exhibited good weather-resistingproperties, but was deficient in its power of resistance to rot anddecay.

From the above it would seem logical that a combination in a singlefabric of an asphaltic and coal tar saturant would prove desirable insecuring a, preservative WlllCll would be universally applicable. Thetendency has been away from the combination of asphalt and coal tar inthe same product, largely for two reasons. Flrst, the manufacturer hasmade a distinction between fabrics intended for weather exposure andthose intended for water-proofing and damp-proofin below-ground and, asindicated above, t ese two uses have appealed to him as falling underthe requirements of two separate problems. He has solved these problemsby making a different fabric for each use. Second, while it has beenrecognized that asphaltic fabrics or sheet materials are best adapted toweather exposure and tar saturated fabrics are best for under groundwork there has been no tendency for the manufacturer to combine tar andasphalt or derivatives of tar with asphalt in a single fabric, for thereason that he has been trained to the belief that asphalt and tar willnot mix. Quoting from Abraham on page 339 of the book referred toBituminous materials which give the diazo reaction (containing phenols)should not be mixed with bituminous substances not giving this reaction.In other words native asphalts, asphaltites and pyrogenous asphaltsshould not be blended with tars or pitches (excepting fatty acid pitch)since it has been found by experience that such mixtures, al 7 thoughthey may melt together perfectly, are not durable or weather-proof. I

It should also be noted that the tendency of manufacturers is to avoidthe inclusion of a liquid constituent in the saturant. If we regard theteaching of the prior art, semisolid tars, pitches, waxes and greasesare used for saturants orfor constituents for saturants. It is true thatsome materials used contain a proportion of liquid material such as softasphalt or tar pitch which contains a proportion of oil, which is liquidat normal temperatures, and a remainder of stiff pitch, but themanufacturer will not entertain the notion of using any liquidconstitutent even if he compensates for it by the addition of acorrespondingly harder pitch, the belief being that the two will notamalgamate properly and permanently.

In my invention I have made a decided departure from the generalpractice, relative to the saturant, by the addition of tar distillatesto mixtures of asphalt and such pitches as may be easily blended withasphalt. As to the coating, the departure from the normal practice ismade by the addition of petroleum grease and parafline wax to theasphalt. While it is not new to vary the proportions of stearin pitch oreven pinctar pitch with asphalt as a saturant, yet the whole trend ofthe art has been to diminish the proportion of such ingredients to thelowest possible amount and in fact to eliminate them altogether.

One of the chief improvement-s contemplated in my present invention asregards the saturant, is the production of a material which will act asa preservative to the fibers of the fabric so that these fibers will notrot or decay in moist locations, or when subjected to the pr esence ofmolds, bacteria and enzymes. To this end a perservative or antisepticmaterial is added to the saturant, and obviously it must be soluble inthe bulk of the saturant, so that it may be carried into the fabric inthe process of saturation. Another improvement lies in the inclusion ofa resinous material which not only exerts a decided preservative action,but imparts to the whole product a characteristic wholesome odor longassociated in themind of the dealer in and user of such materials withrug ed wear and freedom from decay.

One 0 the chief improvements in the coating is the incorporation thereinof inert unsaponifiable materials normally repellant to water andmoisture, and which tend to diminish the brittleness of the asphalticmaterial constituting the major proportion of the coatin My preferredmethod of carrying out my invention is as follows: A good quality ofroofing felt is selected, of a weight preferably from 35 to 75 poundsper 480 square feet, according to the desired weight of the finishedmaterial and preferably of a rag stock comprising in the main cottonrags vwith about ten per cent of woolen rags. An

admixture of burlap up to fifteen per cent is permissible, although ithas been found that burlap is readily destroyed by rot articularly whenused under ground. he

felt should be made into an acceptable sheet according to the usualstandards for such materials, and is then saturated in the manner usualto such class of goods with asaturant composed of 50 pounds softasphalt, 35 pounds pine-tar pitch, 5 pounds pine tar,

5 pounds creosote, 5 pounds soft stearin a penetration of 200, both bythe methods of the American Society for Testing Materials, Standards for1921. The pine-tar pitch and pine tar are the well known articles ofcommerce. The function of these resinous distillates is a dual one; theyexercise a preservative action and impart a wholesome and attractiveodor which is of the utmost importance in its effect on the sale of theproduct. In addition, the pine tar acts as a tempering agent, impartingto the mixture certain characteristics favoring ready working andhandling. The creosote is preferably one which complies with thespecifications of the American Railway Engineering Association, or theAmerican Wood Preservers Association, which specifications may be foundeither in the standards of these associations, or inBulletin 1036 of theUnited States Department of Agriculture. As regardsthe choice betweenthe grades of creosote numbers 1, 2, or 3 of the American RailwayEengineering Association, there is normally not much preference. Thenumber 1 grade is preferable where the fabric is to be exposed toconditions favoring volatilization. Its function is that of apreservative to prevent development or growth of destructive forms. Thestearin pitch may be any commercial stearin pitch having a consistencyapproximating that of the soft asphalt. It conferspliability on themixture.

The fabric which has been saturated with the above described saturant iscoated with a coating consisting of 87 pounds high melting pointair-blown California asphalt, 1.5 pounds parafline wax, 11.5 poundspetroleum grease.

The asphalt used for the coating-should have a softening point ofapproximately 210 F. and a penetration of 20, by the methods of theAmerican Society for Testing Materials Standards for 1921. It has beenfound that an asphalt of these characteristics may be prepared fromCalifornia oil residuum by the oxidizing or the airblown process. Theparatfine wax is the ordinary white parafline wax of commerce, having amelting point of 128 F. It renders the mixture wax-like and relativelynon-adhesive. The petroleum grease is the dark colored petroleum greaseof commerce, and its function is to soften the mixture without undulylowering the melting point. Italso imparts to the compound of which itforms a part, its own characteristic of permanence or stability of form.

The coating may be applied to the saturated felt in. the manner usual tosuch operations, and gives good results when applied in the amount'ofabout 6 pounds on each side, per 100 square feet of fabric. To thecoating thus applied, a dusting of finely ground soapstone, wood flour,-mica, graphite,-or similar material is appliedto prevent adhesion ofadjacent surfaces when wound into rolls.

The usual range of proportions of materials is intended to be covered bythe typical example given. In the example-of coatings disclosed, anespecially high softening point was sought. The softening point of sucha coating has been found in the laboratory to be 195 F. It is possibleto, use coatings having softening points as low as 150 'F. in whichevent much larger proportions of parafiine wax and petroleum grease maybe used. Proportions ranging as high as 3 per cent parafiine wax and 18per cent petroleum grease would not be beyond the possible range. If thefabric were intended for use in cold storage plants as a dam proofmaterial, it is probable that both t e saturant and the coating would besoftened to a point beyond any, test figures characterizing the aboveindicated proportions.

The proportions of the ingredients of the saturant may be variedconsiderably. If the fabrics are intended for roofing, it is possible toreduce the amount of preservative, i. e. creosote or equivalents, andget good results. It is, however, preferred to maintain a goodproportion of preservative in the felt for roofing work, as vegetablefiber saturated with ordinary saturants undergoes 'a distinct loss ofstrength when exposed to weather action. On the other hand it isfrequently advisable to increase the percentage of preservative whendealing with severe exposure underground as on the covering of pipelines laid in filled ground, or wherethere is much alkali in the soil.

It is also obvious that the stearin pitch may be increased at theexpense of the pinetar pitch or vice versa. The amount of asphalt inthesaturant may also be varied particularly as it is well known thatgood results may be had in roof coverings which are wholly asphaltic.

The above named variations in proportions are prompted by considerationsof particular use. -Obviouslyin them, I depart till somewhat from theexpress purpose of my invention which is the making of a fabric havinguniversal adaptability.

While anarrow choice of materials has been mentioned in the aboveexamples it is possible to extend this list considerably. It ispreferred to use asphalt as the ingredient in the largest proportion, inboth the saturant and the coating, on account of its relative cheapnessand because asphalts of excellent quality may be readily procured. Ifcoal-tar pitch, which is the only'alternative material procurable inlarge quantities and at reasonable prices should be contemplated as amajor Constituent of either saturant or coating, orboth, the objectionimmediately arises that coal tar is a poor weather resisting material,compared to asphalt, and furthermore that coal tar is highly susceptibleto differences in temperature, becoming brittle when cold and fluid whenhot.

In' place of pine-tar pitch it is possible to use an increased amount ofasphalt of the proper hardness and a certain increased amount of stearinpitch. To compensate for the loss of preservative constituents thusdisplaced, an'increased amount of creosote may be used, and if we embodythis idea in concrete form'we have atypical formula for the saturant asfollows: 75 poundssoft asphalt as above, 12.5 pounds stearinpitch,7.5-pounds creosote,.5 pounds pine tar.

In this example the additional amount of crensote supplies thepreservative action which otherwise would have been obtained from thepine-tar pitch. Materials other than creosote exert a favorablepreservative action in the saturant. Among these may be mentioned copperresinate and copper oleate. In placeof creosote it is also possible touse a certain proportion of coal tar.

Since coal tar is only about one-fourth as toxic as creosote in itsgermicidal and fungi cidal properties, it is evident that the use ofcreosote is preferable. In place of stearin pitch, petroleum grease maybe used. Wool grease may be substituted in part for stearin pitch, Rosinin small quantities may be incorporated in the saturant and also waxtailings, both of these having the effect of increasing the penetrationof the saturant although they do not contribute permanence to thematerial.

In so far as the coating is concerned similar substitutions may be madetherein. In place of parafline wax, crude scale wax and ozokerite may beused. Substitution for petroleum grease should only be made by.

the use of unsaponifiable materials of similar nature, or by limitedamounts of substances having low percentages of. saponifiableingredients. Petroleum oils of high viscosity, wool grease in limitedquantity and wax tailin'gs in limited amount may be substituted in partfor'the petroleum grease.

It may be well to observe that if desired various fillers such asgraphite, silica and mica may be added to the coating.

It is obvious that asbestos paper may be employed instead of rag felt asa base. In this case the preservative is of immense value in protectingthe organic sizing materials, such as starch, and dextrine which areused to give strength to the asbestos sheet. Burlap or cotton fabricsmay also be used as a base for the sheet of material, burlap beingespecially benefited by the types .of saturant and coating aboveexplained since it is normally readily subject 8 to decay when exposedto the weather or used under ground.

I claim: 7

1. A sheathing material comprising a fibrous base saturated with acompound comprising asphalt, stearin pitch and creosote.

2. A sheathing material comprising a librous base saturated with acompound comprising asphalt, stearin pitch and creosote, and coated witha compound comprising asphalt and petroleum grease. v

3. A sheathing material comprising a fibrous base saturated with acompound comprising asphalt, stearin pitch and creosote, and coated witha compound comprising asphalt, petroleum grease and paralnne.

4. A sheathing material comprising a fibrous base saturated with acompound comprising asphalt, stearin pitch, creosote and a resinousdistillate.

5. A sheathing material comprising a fibrous base saturated with acompound comprising asphalt, stearin pitch, creosote, and pine-tarpitch.

6. A sheathing material comprising a fibrous base saturated with acompound comprising asphalt, stearin pitch, creosote, pinetar pitch andpine tar.

7 A sheathing material comprising a fibrous base saturated with acompound comprising asphalt, stearin pitch, creosote and a ,resinousdistillate, and said saturated base being coated with a compoundcomprising asphalt and a stable grease.

8. A sheathing material comprising a fibrous base saturated with acompound comprising asphalt, stearin pitch, creosote and a resinousdistillate, and said saturated base being coated with a compoundcomprising asphalt and petroleum grease.

9. A sheathing material comprising a fibrous base saturated with acompound comprising asphalt, stearin pitch, creosote and a resinousdistillate, and said saturated base being coated with. a compoundcomprising asphalt petroleum grease and parafiine.

10. A sheathing material comprising a fibrous base saturated with acompound comprising asphalt, stearin pitch, creosote, and pine-tarpitch, and said saturated base 13 being coated with a compoundcomprising pounds inc-tar pitch, 5 pounds pine tar, asphalt, petroleumgrease and parafline. 5 poun s creosote, 5 pounds soft stearin 11. Asheathing material comprising a pitch.

fibrous base saturated with a compound com- Formula C 87 poundsair-blown asphalt,

5 prising the ingredients named in Formula 1.5 pounds parafline, 11.5pounds petroleum 15 S substantially in the proportions stated, grease.and coated with a compound comprising In testimony whereof, I havehereunto the ingredients named in Formula C subset my hand. stantiallyin the proportions stated:

Formula S: 50 pounds soft asphalt, 35 DOHER FINLEY.

